Find the interval of all $x$ such that $1-3x < x \le 1-x$. Give your answer in interval notation, simplifying any fractions which appear in your answer.
We have two inequalities
1 - 3x < x x ≤ 1 - x
1 < x + 3x x + x ≤ 1
1< 4x 2x ≤ 1
1/4 < x x ≤ 1/2
x > 1/4
(1/4 , 1/2]
thank you daddy cphill!
